RMAN Backup With Compression

I repeated the test from the previous post but this time I tried to compress the backup. At this stage I need your help. I believe I have used the free compression which does not require an extra licence. If somebody who knows more about this than me could add a comment below, telling me if I am right or wrong, that would be very helpful. I backed up the database as before:

C:\Users\AJ0294094>rman nocatalog target=andrew/reid

Recovery Manager: Release 11.2.0.1.0 - Production on Fri Mar 11 19:19:38 2016

Copyright (c) 1982, 2009, Oracle and/or its affiliates.  All rights reserved.

connected to target database: DEBELDV2 (DBID=4080010922, not open)

using target database control file instead of recovery catalog

RMAN> backup as compressed backupset database;

Starting backup at 11-MAR-16

allocated channel: ORA_DISK_1

channel ORA_DISK_1: SID=156 device type=DISK

channel ORA_DISK_1: starting compressed full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

input datafile file number=00001 name=E:\ORACLE\ORADATA\DEBELDV2\SYSTEM01.DBF

input datafile file number=00003 name=E:\ORACLE\ORADATA\DEBELDV2\UNDOTBS01.DBF

input datafile file number=00002 name=E:\ORACLE\ORADATA\DEBELDV2\SYSAUX01.DBF

input datafile file number=00004 name=E:\ORACLE\ORADATA\DEBELDV2\USERS01.DBF

channel ORA_DISK_1: starting piece 1 at 11-MAR-16

channel ORA_DISK_1: finished piece 1 at 11-MAR-16

piece handle=E:\ORACLE\FLASH_RECOVERY_AREA\DEBELDV2\DEBELDV2\BACKUPSET\2016_03_1

1\O1_MF_NNNDF_TAG20160311T192012_CG632XB5_.BKP tag=TAG20160311T192012 comment=NO

NE

channel ORA_DISK_1: backup set complete, elapsed time: 00:01:15

channel ORA_DISK_1: starting compressed full datafile backup set

channel ORA_DISK_1: specifying datafile(s) in backup set

including current control file in backup set

including current SPFILE in backup set

channel ORA_DISK_1: starting piece 1 at 11-MAR-16

channel ORA_DISK_1: finished piece 1 at 11-MAR-16

piece handle=E:\ORACLE\FLASH_RECOVERY_AREA\DEBELDV2\DEBELDV2\BACKUPSET\2016_03_1

1\O1_MF_NCSNF_TAG20160311T192012_CG6359MJ_.BKP tag=TAG20160311T192012 comment=NO

NE

channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01

Finished backup at 11-MAR-16

RMAN> exit

Recovery Manager complete.

C:\Users\AJ0294094>

... and when I checked the size of the backup on disk, it was roughly a quarter of the size of the backup I did before:

E:\oracle\flash_recovery_area\DEBELDV2\DEBELDV2\BACKUPSET\2016_03_11>dir

Volume in drive E is Seagate Backup Plus Drive

Volume Serial Number is 6E45-7AAF

Directory of E:\oracle\flash_recovery_area\DEBELDV2\DEBELDV2\BACKUPSET\2016_03_

11

03/11/2016  07:21 PM    <DIR>          .

03/11/2016  07:21 PM    <DIR>          ..

03/11/2016  07:21 PM         1,097,728 O1_MF_NCSNF_TAG20160311T192012_CG6359MJ_.

BKP

03/11/2016  07:21 PM       235,659,264 O1_MF_NNNDF_TAG20160311T192012_CG632XB5_.

BKP

               2 File(s)    236,756,992 bytes

               2 Dir(s)  579,868,397,568 bytes free

E:\oracle\flash_recovery_area\DEBELDV2\DEBELDV2\BACKUPSET\2016_03_11>